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Jan 27, 2009

NXT + PF Battle Tank

This "Battle Tank" creation uses parts from the NXT (8527) set and the 8275 Power Functions Bulldozer set (sadly, no longer available from LEGO). It combines the NXT and two NXT motors with a LEGO Power Functions setup of 2 XL motors, 1 M motor, 2 IR receivers, and 1 PF battery pack, and various parts from both sets. The whole model was designed from scratch from the ground up. The treaded chassis in particular outperforms the bulldozer chassis in several ways I think (faster, climbs better, treads don't fall off when turning on carpet, more compact, fewer parts), in addition to making space in the center down low for the NXT brick. I built this and filmed the video clips a while back but never got around to editing and posting the video. But now that I am on a roll with remote control...

The NXT part of this is not that complex or interesting, with one notable exception: I found a way to get the Power Functions IR receiver to give sensor input to the NXT, so that you can partially control NXT creations using the PF remote control, which is what made this project possible. I will blog on the details of this in a separate post.

I also put the ultrasonic sensor on it so that I could do something autonomous with it too, but I never got around to it because the remote control was too much fun :-). And then I needed the parts so I took it all apart...

8 comments:

For sure, I would certainly not shoot (or poke or saw) my cat! She is my assistant. She sits on my lap when I program and lays on my parts when I build (and she likes the blue and red NXT balls especially)...

Awesome build! I actually just spent the last couple of hours working a similar tank using the treads from the 8294 excavator and NXT motors that will pick up and launch tennis balls for my dog to chance down. Controlling everything from an IR remote would be perfect... I can't wait to read your follow up post.

i really love it. good job(im so mad about the nxt 2.0... if it doesntr get the same soft ware as nxt 1.0 ima blow something up, lol... i really want it now, now isnt a good time though i just got my first -.-... was planing on geting resource set for both kinds of kits though then buy nxt 2) side note: im thinking about the bull dozer set :D

Very cool! I am new to this Lego Mindstorm NXT topic, I would like to know, if it´s possible to use the Power Function Motors with this NXT "processing unit"? I would like to built a device which is capable of rotating 5kg weight mounted on a plate. If it´s possible, how precise are the Power Function Motors concerning the amount of degrees I want to rotate them?

Gernot, it's easy to power the PF motors with the NXT using adapter wires, but the motors don't give any rotation feedback, so you have no control over degrees other than timing it, and if I remember correctly, you can't even "brake" a PF motor (it just coasts when you stop).

If what you are looking for is a smaller or less strangely-shaped NXT motor, join the club! If what you want is more power or more speed, you can usually solve that with gears.

Thank you, Dave. I think I will need a precise control, so maybe, the "normal" NXT will be suitable for my task.

Maybe I can ask another question, although it´s a little off-topic here, but I know that you know the answer for sure:

How many "blocks" in the programming software are allowed, is there a limit? For example, is it possible to to a 360° rotation step by step with interrupts (as far as I understand, I would need to program a 1° movement 360 times, a pause inbetween these steps)?

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